Waterdispersible cationic resins for electrodeposition

Abstract

Waterdispersible cationic resins are formed by reacting the components comprising at least (A) an epoxidized polydiene, (B) a bisglycidylether of a polyphenol, (C) an amide compound, which is formed by one or more higher, substantially multiply unsaturated fatty acids and a polyamine and which may comprise a ketimine group or a hydroxy group, and possibly (D) an organic secondary amine and/or (E) a partially and/or fully masked polyisocyanate, which product comprises excess epoxide groups and carbon-carbon double bonds and which resins can be made waterdispersible with an acid under formation of cationic groups. A composite is provided comprising the cationic resin superposed on a conducting substrate and a method is described for forming the composite.

What is claimed is: 
     
       1. Water dispersible cationic resins for obtaining films with low pin hole formation and improved breakdown voltage, comprising the product of reaction of at least (A) an epoxidized polydiene,   (B) a bisglycidylether of a polyphenol,   (C) an amide compound, which is formed by one or more higher, substantially multiply unsaturated fatty acids and a polyamine and which may comprise a ketimine group or a hydroxy group, and if necessary   (D) an organic secondary amine, at temperature from about 100° to 150° C., and/or   (E) a partially and/or fully masked polyisocyanate, at temperature below about 100° C., which product comprises excess epoxide groups and carbon-carbon double bonds.   
     
     
       2. The waterdispersible resin according to claim 1 wherein the resins are rendered waterdispersible by formation of cationic groups in the presence of an acid. 
     
     
       3. The waterdispersible resins according to claim 1 wherein the organic secondary amine is diethylamine and/or methylethanolamine and/or diethanolamine. 
     
     
       4. The waterdispersible resins according to claim 1 wherein the partially or fully masked polyisocyanate is 4,4'-diisocyanato-diphenylmethane or toluenediisocyanate reacted with a member of the group consisting of ethyleneglycolmonomethylether, ethyleneglycolmonoethylether, butanol, 2-ethylhexanol-1, 2-hydroxyethylmethacrylate, 2-hydroxypropylmethacrylate and mixtures thereof. 
     
     
       5. The water dispersible resins according to claim 1, wherein said epoxidized polydiene is a member of the group consisting of polybutadiene-1,2, polybutadiene-1,4, polybutadiene-(1,2;1,4), derivatives and mixtures thereof. 
     
     
       6. The waterdispersible resins according to claim 1 wherein the components (B) is derived from bisphenol A. 
     
     
       7. The waterdispersible resins according to claim 1 wherein component (C) is based upon ricinenic fatty acids and wherein the acid amide groups are essentially derived from compounds having the structural formula   C.sub.17 H.sub.31 --CO--NH--CH.sub.2 --CH.sub.2 --NH--CH.sub.2 --CH.sub.2 --R.sub.1     wherein C 17  H 31  represents the hydrocarbon group of ricinenic acid substantially containing 9,11- and 9,12-octadecadienic acid and R 1  represents --NH--CO--C 17  H 31 , wherein C 17  H 31  represents the hydrocarbon group of ricinenic acid or ##STR13## wherein R 2  is an alkyl group with from 1 to 2 carbon atoms and wherein R 3  is an alkyl group with from 1 to 4 carbon atoms or --OH.   
     
     
       8. The waterdispersible resins according to claim 7 wherein the acid amide groups are derived substantially from mixtures of compounds of the formula ##STR14## wherein C 17  H 31  represents the hydrocarbon group of ricinenic acid. 
     
     
       9. The waterdispersible resins according to claim 1 wherein the higher fatty acids are based on linseed fatty acids and wherein the acid amide groups are derived from compounds having the structural formula   R.sub.1 --CO--NH--CH.sub.2 --CH.sub.2 --NH--CH.sub.2 --CH.sub.2 --R.sub.2     wherein R 1  represents the hydrocarbon group of the acids substantially contained in linseed fatty acids including linolenic acid, linolic acid and oleic acid and wherein R 2  represents --NH--CO--R 1  wherein R 1  represents the hydrocarbon group of the acids substantially contained in linseed fatty acids or ##STR15## wherein R 3  is an alkyl group with 1 to 2 carbon atoms and R 4  is an alkyl group with from 1 to 4 carbon atoms or --OH.   
     
     
       10. The waterdispersible cationic resins according to claim 1 wherein the weight ratios of the components (A) to (B) to (C) to (D) is about 1000 to (1000-3000) to (250-3000) to (25-500) and wherein the epoxide content of (A) is from about 2 to 7 of epoxy equivalents per 1000 g of component (A) and wherein the epoxide content of (B) is from about 1 to 6 of epoxy equivalents per 1000 g of component (B). 
     
     
       11. The waterdispersible cationic resins according to claim 1 wherein the weight ratio of the components (A) to (B) to (C) to (D) to (E) is about 1000 to (1000-3000) to (250-3000) to (25-500) to (20-3000) and wherein the epoxide content of (A) is from about 2 to 7 of epoxy equivalents per 1000 g of component (A) and wherein the epoxide content of (B) is from about 1 to 6 of epoxy equivalents per 1000 g of component (B). 
     
     
       12. The waterdispersible cationic resins according to claim 1 wherein the weight ratio of the components (A) to (B) to (C) to (E) is about 1000 to (1000-3000) to (500-3000) to (20-3000) and wherein the epoxide content of (A) is from about 2 to 7 of epoxy equivalents per 1000 g of component (A) and wherein the epoxide content of (B) is from about 1 to 6 of epoxy equivalents per 1000 g of component (B). 
     
     
       13. The waterdispersible cationic resins according to claim 1 wherein the component (B) is a bisglycidylether of bisphenol A. 
     
     
       14. The waterdispersible cationic resins according to claim 1 wherein the weight ratio of the components (A) to (B) to (C) is about 1000 to (1000-3000) to (500-3000) and the epoxide content of (A) is from about 2 to 7 of epoxy equivalents per 1000 g of component (A) and the epoxide content of (B) is from about 1 to 6 of epoxy equivalents per 1000 g of component (B). 
     
     
       15. The waterdispersible cationic resins according to claim 1 further comprising water in a weight ratio of water to the cationic resin of from about 3 to 20. 
     
     
       16. The waterdispersible cationic resins according to claim 1 as resulting after baking at a temperature of from about 150° to 200° C.